An evaluation of the complete replacement of both fishmeal and fish oil in diets for juvenile Asian seabass, Lates calcarifer

An experiment was conducted to examine the potential for the complete replacement of fishmeal (FM) and fish oil (FO) in diets for barramundi,Lates calcarifer. A series of diets were formulated to the same digestible protein and energy specifications, but which were designed with FM inclusion levels at 300, 200, 100 or 0g/kg and FO at 100%, 30%, 15% or 0% of the added oil in the diets (4×4 factorial design). Ricebran oil was the alternative oil used in the growth study, while soybean meal and poultry meal were the main alternative protein sources used. For the growth study, fish of an initial weight of 154.4±1.1g were randomly allocated across 48 tanks (three replicates per treatment). After eight weeks, the average weight gain across all treatments was 187.7±2.3g/fish and feed conversion across all treatments averaged 1.04±0.01 feed/gain. A significant effect of FM on both feed intake and weight gain was observed, and this was observed as early as within the first few weeks, but no similar such effect was observed with FO. No effects were observed on protein deposition efficiency, though both lipid and energy deposition efficiencies were affected by FM level. The reduction in FO had a notable effect on the fatty acid composition of the diets and subsequently the fish fatty acid composition. Expression of key LC-PUFA metabolism genes in the liver of the fish was influenced by both FM and FO levels, but was only significant at the extremes of the treatment ranges. The results from this study demonstrate that there is clear potential to replace almost all the FM content of barramundi diets without loss of fish performance, up to and including diets with as little as 100g/kg fishmeal. Replacement of fish oil was more successful with the ability to completely replace all FO demonstrated at all but the lowest inclusion levels of FM. These results clearly demonstrate that the near complete replacement of both FM and FO in barramundi diets is a technical reality

Effects of different commercial diets on growth performance, health and resistance to Tetrahymena sp. infection in guppies, Poecilia reticulata (Peters)

The effects of feeding guppy fry, Poecilia reticulata (Peters), different commercial diets from BernAqua [MeM (R=Regular, O=Ornamental and P=Premium) and experimental feed (EF] and Ocean Nutrition (ON) on growth was tested for 57days. Health status and resistance to Tetrahymena infection were analysed at the end of the trial. The highest growth was obtained in fish fed MeM Regular and MeM Premium (mean final weights of 427 and 417mg respectively). Fish fed EF had a significantly higher rate of spinal deformity (12.7%) than all other feeding groups (3.05% or less). Histological analysis revealed the accumulation of liver glycogen and/or lipid in fish from all feeding groups; fat accumulation in the abdomen was most pronounced in the EF and MeM Regular-fed fish, and muscle dystrophy was observed in ca. 50% of the fish from all feeding groups except the MeM Ornamental-fed group. The highest mortality following Tetrahymena infection occurred in fish fed EF (87%) and the lowest mortality in the MeM Ornamental-fed fish (58%). Mortalities in all other feeding groups ranged between 69% and 76%. In summary, MeM Ornamental feed provided a moderate weight gain, no muscle dystrophy, negligible deformity and the greatest resistance to parasitic infection

Does Japan Still Matter? Past Tendencies and Future Opportunities in the Study of Japanese Firms

This paper engages with the question ‘does Japan still matter’ by systematically reviewing publication patterns in peer-reviewed academic journal articles addressing Japanese firms and their management practices, illustrating the academic discourse surrounding Japanese firms over four decades, and by identifying future research opportunities. Initially, particularly from the 1980s when Japanese firms came to prominence, these practices tended to be identified as ‘best practice’. However, at least in part due to socio-economic changes, this tendency has become less prominent since the ‘bubble economy’ burst. Instead, three broader developments are observed: the examination of the continuity and change in the traditional Japanese model, a more complex approach that involves multiple themes of research, and leveraging new contexts to examine Japanese firms, including the long-term recession, the rise of the East Asian economy, and the increasing importance of corporate social responsibility